UN nuclear experts will visit Iran on Saturday to prepare for a deal curbing the Islamic republic's atomic programme two days before it takes effect, an official in Tehran said.

The International Atomic Energy Agency "experts will visit Tehran on January 18 to prepare for the implementation of the Geneva agreement," IRNA news agency quoted Behrouz Kamalvand, spokesman for Iran's Atomic Energy Organisation, as saying on Monday.

Tehran agreed in November to roll back parts of its nuclear work and halt further advances in exchange for the release of billions of dollars in frozen assets and limited relief from the sanctions that have choked its economy.

The interim agreement between Iran and the so-called P5+1 -- UN Security Council permanent members Britain, France, China, Russia and the United States plus Germany -- will take effect on January 20.

"Much of the joint action plan between Iran and the P5+1 group concerns agreements between us and the IAEA," said Kamalvand.

"We are negotiating with the parties regarding inspections and surveillance" of Iran's nuclear programme that the IAEA must carry out, he was quoted as saying.